Making a mold out of tufa stone was discussed in a previous post, but how did the Navajo mass produce some of their work if the mold would only work for a small number of pieces? In the mid 1800’s the Navajo started a process that is known as sandcasting. The whole process from start to finish is labor intensive and can easily take several days. The first part involves creating a master sample that will be utilized to cast all other pieces. The master is created by using the tufa stone mold.
The next step uses the piece that has been taken from the mold. The piece is set in a frame with removable, wooden faces facing up and a dry cement and oil mixture is packed very tightly over it to capture all the details of the piece. A top is set on the frame, and the whole thing is flipped over so the silver is now lying visibly on the top. It is gently removed so the detail is preserved in the “sand” mixture. Channels and air vents are carefully cut in the sand and a piece of smooth tufa is secured over the frame. Just as with the stone mold, the molten silver is poured into the mold. The piece is quickly removed with pliers and any extra metal, or slag, is removed before it cools. The mold is again destroyed, but the original piece can be used as many times as needed to make duplicates
